This invention relates to an improved system for using electricity to stimulate production of viscous hydrocarbons from subsurface formations. More particularly, a single well system is divided into a long metal overburden electrode and a relatively short metal electrode in the oil pay zone formation.
Large relatively shallow deposits of viscous hydrocarbonaceous substances whose viscosity is decreased by heat, like for example, the Ugnu formation in Alaska, are known to exist in subterranean formations. Many techniques have been proposed for tar sands, viscous crude oils and other similar hydrocarbons. Relatively recently it has been proposed to use electrical current to add heat to a subsurface pay zone containing tar sands or viscous oil. Two electrodes are connected to an electrical power source and are positioned at spaced apart points in contact with the earth. Although a single well system has been proposed, it has generally been believed that a single well system is not economically feasible. The patented art, for example, U.S. Pat. Nos. 3,642,066; 3,874,450; 3,848,671; 3,948,319; 3,958,636; 4,010,799 and 4,084,637 stress passing current between laterally spaced apart electrodes.